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<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
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<body>
    
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<script> 
 function  fun1(){}

 const  fun2 = ()=>{}

let  f3 = function(x){
    console.log(x  );
}
f3 = x =>{
    console.log (x  );
}

f3 = _ =>{
    console.log("abc");
}
//  无参的箭头函数
f3= _ =>{    
    console.log("abc");
}
f3();

f3=(x,y) =>{
    console.log("abc");
    return 1234;
}

f3=(x,y)=> x + y ;

f3= _ =>    console.log(1234);


f3= (age,name) =>    ({ x: age, name: name});

 

</script>